Polymers including a methylene beta-ketoester and products formed therefrom

ABSTRACT

The present teachings are directed at 1,1-di substituted alkene monomers (e.g., methylene beta-ketoester monomers), methods for producing the same, polymerizable compositions including a methylene beta-ketoester monomer, and polymers, compositions and products formed therefrom. The monomer preferably is a high purity monomer. In the method for producing the methylene beta-ketoesters of the invention, a beta-ketoester may be reacted with a source of formaldehyde. The methylene beta-ketoester monomers may be used in monomer-based products (e.g., inks, adhesives, coatings, sealants or reactive molding) and polymer-based products (e.g., fibers, films, sheets, medical polymers, composite polymers and surfactants).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part and claims priority to U.S.patent applications Ser. No. 15/363,169 filed on Nov. 29, 2016 (attorneydocket number 1781.015USD1) and Ser. No. 14/868,795 filed on Sep. 29,2015 (attorney docket number 1781.014C1, the contents of which are eachincorporated herein by reference in its entirety.

U.S. patent application Ser. No. 15/363,169 is a divisional patentapplication of U.S. patent application Ser. No. 14/352,406 which is a 35U.S.C. § 371 National Phase Application of International PCT ApplicationNo. PCT/US2012/060837, filed Oct. 18, 2012 which application claims thebenefit of priority to U.S. Provisional Patent Applications 61/549,092,filed Oct. 19, 2011; 61/549,104, filed Oct. 19, 2011; and 61/549,152,filed Oct. 19, 2011; each incorporated herein by reference in itsentirety.

U.S. patent application Ser. No. 14/868,795 is a continuation-in-partpatent application claiming priority to U.S. patent application Ser. No.14/352,369 filed on Apr. 17, 2014, Ser. No. 14/075,334 filed on Nov. 8,2013, and Ser. No. 14/810,741 filed on Jul. 28, 2015, each incorporatedherein by reference in its entirety. U.S. patent application Ser. No.14/352,369 is a 35 U.S.C. § 371 National Phase Application ofInternational PCT Patent Application PCT/US2012/060840, filed on Oct.18, 2012, which application claims the benefit of priority to U.S.Provisional Patent Applications 61/549,104, filed on Oct. 19, 2011,61/549,092, filed on Oct. 19, 2011, and 61/549,152 filed on Oct. 19,2011, each incorporated herein by reference in its entirety. U.S. patentapplication Ser. No. 14/075,334 is a continuation of U.S. patentapplication Ser. No. 13/880,438, filed on Jul. 22, 2013 which is a U.S.National Stage application under 35 U.S.C. § 371 of International PatentApplication PCT/US2011/056903, filed Oct. 19, 2011, which InternationalPatent Application claims the benefit of priority of U.S. ProvisionalPatent Applications 61/405,029, filed Oct. 20, 2010, 61/405,049, filedOct. 20, 2010, 61/405,078, filed Oct. 20, 2010, 61/405,033, filed Oct.20, 2010, 61/405,056, filed Oct. 20, 2010, 61/523,311, filed Aug. 13,2011, and 61/523,705, filed Aug. 15, 2011, each incorporated herein byreference in its entirety. U.S. patent application Ser. No. 14/810,741claims priority to U.S. patent application Ser. No. 14/789,178 filed onJul. 1, 2015 and U.S. Provisional Patent Applications 62/186,479 filedon Jun. 30, 2015, 62/182,076 filed on Jun. 19, 2015, 62/047,283 filed onSep. 8, 2015, and 62/047,328 filed on Sep. 8, 2015, each incorporatedherein by reference in its entirety.

INCORPORATION BY REFERENCE

All documents cited or referenced herein and all documents cited orreferenced in the herein cited documents, together with anymanufacturer's instructions, descriptions, product specifications, andproduct sheets for any products mentioned herein or in any documentincorporated by reference herein, are hereby incorporated by reference,and may be employed in the practice of the invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a new class of methylene beta-ketoestermonomers, to methods of producing or synthesizing such monomers, and tothe use and application of such monomers as commercial products andcompositions, including, for example, monomer-based products (e.g.,inks, adhesives, coatings, sealants or reactive molding) andpolymer-based products (e.g., fibers, films, sheets, medical polymers,composite polymers and surfactants).

The new monomers relate to a platform of methylene beta-ketoestermonomers having the general structural formula:

Products produced with such monomers include, for example, polymerizablecompositions and polymers formed therefrom, e.g., inks, adhesives,coatings, sealants, reactive moldings, fibers, films, sheets, medicalpolymers, composite polymers and surfactants.

2. Background

Methylene malonate monomers have been disclosed for example in U.S. Pat.Nos.: U.S. Pat. Nos. 2,313,501; 2,330,033; 3,221,745; 3,523,097;3,557,185; 3,758,550; 3,975,422; 4,049,698; 4,056,543; 4,160,864;4,931,584; 5,142,098; 5,550,172; 6,106,807; 6,211,273; 6,245,933;6,420,468; 6,440,461; 6,512,023; 6,610,078; 6,699,928; 6,750,298; andPatent Publications 2004/0076601; WO/2012/054616A2; WO2012/054633A2.

As described in certain of those publications, methylene malonates havethe potential to form the basis of a large-scale platform of rawmaterials useful in a wide variety of chemical products.

While various earlier methods for producing methylene malonates havebeen known for many years, these prior methods suffer significantdeficiencies which preclude their use in obtaining commercially viablemonomers. Such deficiencies include unwanted polymerization of themonomers during synthesis (e.g., formation of polymers or oligomers oralternative complexes), formation of undesirable side products (e.g.,ketals or other latent acid-forming species which impede rapidpolymerization), degradation of the product, insufficient and/or lowyields, and ineffective and/or poorly functioning monomer product (e.g.,poor adhesive characteristics, stability, or other functionalcharacteristics), among other problems. The overall poorer yield,quality, and chemical performance of the monomer products formed byprior methods has impinged on their practical use in the production ofthe above commercial and industrial products. No viable solutions tosolve the aforementioned problems have yet been proposed, acceptedand/or recognized and certainly do not exist currently in the industry.

For example, in U.S. Pat. No. 2,330,033 to Gaetano D'Alelio (“the '033patent”), methylene malonic esters are prepared by condensing a malonicester with formaldehyde under alkaline conditions, acidifying withacetic acid and dehydrating the mass and distilling the methylenemalonic ester. In each example of the '033 patent, the condensationreaction is acidified using acetic acid. Furthermore, the ester isdescribed as polymerizing spontaneously in the absence of inhibitors.Thus, the reaction conditions described in the '033 patent would haveled to the undesirable premature polymerization of the monomer and theproduction of deleterious side products. Further, the reference does noteven recognize the formation of such deleterious side products, letalone does it provide any teachings or suggestions as to how to avoid oreliminate the formation of these impurities. Accordingly, the methylenemalonates purportedly formed by this process are impractical for use inthe production of viable commercial and industrial products.

Similarly, in U.S. Pat. No. 2,313,501 to Bachman et al. (“the '501patent”), methylene dialkyl malonates are prepared by the reaction ofdialkyl malonates with formaldehyde in the presence of an alkali metalsalt of a carboxylic acid in a substantially anhydrous carboxylic acidsolvent. The method of the '501 patent purports to provide higher yieldsthan the prior methods of condensing formaldehyde with a dialkylmalonate in the presence of a base. In the '501 patent, methylenediethyl malonate is distilled directly from the reaction mixture undersub-atmospheric pressure. The ester is described as forming a soft waxywhite polymer upon standing, indicating the presence of a high degree ofdeleterious side products. The '501 patent does not even recognize theformation of such deleterious side products, let alone does it provideany teachings or suggestions as to how to avoid or eliminate theformation of such impurities. Thus, the methylene malonates purportedlyformed by this process are highly unstable and are impractical for usein the production of viable commercial and industrial products.

Furthermore, in U.S. Pat. No. 3,197,318 to Halpern et al. (“the '318patent”), di alkyl methylene malonic acid esters are prepared bycondensing dimethylmalonate with formaldehyde in the presence of aceticacid and an acetate of a heavy metal at 100-110° C. The reaction mixtureis directly distilled under reduced pressure. The '318 patent statesthat in the anhydrous composition, the reaction either fails to occur oris greatly delayed by the inhibitor up to the time when theeffectiveness of the inhibitor is reduced by contact of moisturetherewith (from occluded surface water on glass, metal or the like). Theunfavorable reaction conditions described in this reference would haveled to the production of deleterious side products. The '318 patent doesnot even recognize the formation or presence of these impurities, letalone offer teachings or suggestions as to how to avoid or eliminatetheir formation. Accordingly, the methylene malonates purportedly formedby the process of the '318 patent would have been impractical for theiruse in the production of viable commercial products.

Also, in U.S. Pat. No. 3,221,745 to Coover et al. (“the '745 patent”),monomeric dialkyl esters of methylene malonic acid are purportedlyprepared in high purity because even with small amounts of impuritiesthat influence polymerization the adhesive utility will be impaired. The'745 patent describes removing all impurities to levels below 100parts-per-million preferably below 10 parts-per-million. The monomersare prepared by hydrogenating the olefinic bond of a dialkylalkoxy-methylenemalonate in the presence of a hydrogenation catalyst andpyrolyzing the reaction product. The '745 patent states that these highpurity materials polymerize and form firm bonds in situ rapidly, withinseconds. Indeed, the '745 patent, like related U.S. Pat. No. 3,523,097to Coover et al. (“the '097 patent”), requires the use of an acidicstabilizer to enhance shelf-life and to prevent prematurepolymerization. However, the high temperature conditions of thepyrolysis reaction invariably results in the formation of unwanted anddeleterious side products and is a much more expensive and difficultsynthesis process for preparing methylene malonate as compared to theKnovenagel reaction with formaldehyde. Thus, the monomer purportedlyformed by the processes of the '745 and '097 patents is impractical foruse in the production of viable commercial and industrial products.

Still further, in U.S. Pat. No. 3,758,550 to Eck et al. (“the 550patent”) report on a general process for producing methylene malonicesters of the general formula CH₂═C(—CO₂R)₂, by reactingparaformaldehyde in glacial acetic acid in the presence of a catalyst toform a product in the form of a “gel” which is then “cracked” at hightemperature distillation. The reaction is conducted over long periods oftime, including up to 15 hours, and produces a substantial amount ofdeleterious side products, as evidenced by the gelatinouscharacteristics of the product. Further, the '550 patent contains nosupport showing the functionality of the monomers produced. Due to thelikely presence of high levels of impurities, the functionality of themonomers produced by the '550 patent would likely be substantiallycompromised.

Citing numerous disadvantages of the foregoing processes, whichdisadvantages were said to make them difficult, if not impossible, toprovide commercially viable monomers, Bru-Magniez et. al. (U.S. Pat.Nos. 4,932,584 and 5,142,098) (“the '584 and '098 patents”) developed aprocess whereby anthracene adducts were prepared by reacting mono- ordi-malonic acid ester with formaldehyde in the presence of anthracene,most preferably in a non-aqueous solvent medium in the presence ofselect catalysts. According to these patents, the anthracene adductswere said to be readily produced in high yields with the desiredmethylene malonates obtained by stripping them from the anthraceneadduct by any of the known methods including heat treatment,thermolysis, pyrolysis or hydrolysis; preferably heat treatment in thepresence of maleic anhydride. The resultant crude products were thensubjected to multiple distillations, preferably lower temperaturedistillations under vacuum, to recover the purified methylene malonates.Despite the claim to high yields, their crude yields were generally inthe range of 21-71%, and more importantly, nothing is taught withrespect to the purity of the material obtained.

While the use of intermediate adducts promoted higher yields and allowedgreater versatility, particularly with respect to the broader variety ofmethylene malonates capable of being produced, lingering problemspersisted, namely batch-to-batch inconsistency and the generalinstability of the process as well as the so-formed crude and finalproducts, especially in bulk storage, and of formulated products, suchas adhesives, made with the same. Additionally, the adduct routesinvolve considerable added expense, particularly in light of the needfor the additional reactants and other materials, added production stepsand time, new energy requirements and environmental concerns, and thelike. Furthermore, despite their advances, these processes have yet tofully or even adequately address, particularly from a commercialviability standpoint, the underlying and critical problems evidenced bythe continuing inconsistency in the production of the methylidenemalonates, particularly as reflected by the ongoing instability of thereaction mix particularly during the distillation and recovery of thedesired product as well as of the recovered product. It is this erraticnature of the production process and resultant product and the attendantcosts associated therewith that compromises and overshadows thecommercial value and opportunity for these products.

Similar conclusions may be drawn from other representative priorreferences that purport to teach the synthesis of methylene malonates,including, for example, U.S. Pat. Nos. 3,557,185; 3,975,422; 4,049,698;4,056,543; 4,160,864; and 6,106,807. None of these references, however,recognize the same problems discussed above, including the formation ofdeleterious side products, such as, ketals and other latent acid-formingspecies which impede monomer performance, the occurrence of unwantedpolymerization (e.g., unintended formation of polymers, oligomers oralternative complexes) and the general degradation and instability ofthe monomer products which together substantially impedes the productionof high-quality methylene malonate monomers having commercial viability.

In view of the above art, there remains no known single viablecommercially suitable method or process for the chemical synthesis ofmethylene malonate monomers which may be utilized to produce theseimportant raw materials for the generation of a wide variety ofcommercial and industrial products. Thus, a need exists for improvedmethods for synthesizing methylene malonate monomers that are capable ofbeing viably used in commercial and industrial applications.

The present invention solves the aforementioned problems in thesynthesis of methylene malonate monomers and paves the way to acommercially viable source of an important raw material.

Free radical polymerization of dialkyl methylene malonate monomers usingheat, UV light and peroxide is described in U.S. Pat. Nos. 2,330,033 and2,403,791, both incorporated herein by reference. In these patents, themonomer was prepared using traditional methods which results in lowpurity monomer. The polymer examples in these patents are all preparedvia bulk polymerization. One would therefore not expect to be able tocontrol polymer properties, such as molecular weight and molecularweight distribution.

It is envisioned that methylene beta-ketoester monomers and theirassociated monomeric and polymeric-based products would be useful inindustrial, consumer, and medical applications. Specifically, methylenebeta-ketoester monomers would provide a benefit over other monomers inthat the incorporation of a ketone group adjacent to the activemethylene group reduces the susceptibility of degradation of the monomerupon utilization or further functionalization. Indeed, unlike many othermonomers, methylene beta-ketoester monomers and their products can beproduced via sustainable routes as well as be designed to beenvironmentally benign, biologically benign and as such many of theproducts can be generally regarded as “green.”

Thus, there exists a need in the art for methods of synthesizing novelmethylene beta-ketoester monomers, formulating novel polymerizablecompositions, and providing polymer products based on this platform.

SUMMARY OF THE INVENTION

The purpose and advantages of the present invention will be set forth inand apparent from the description that follows. Additional advantages ofthe invention will be realized and attained by the methods and systemsparticularly pointed out in the written description and claims hereof,as well as from the appended drawings.

In one aspect, the invention provides a methylene beta-ketoester monomerhaving a structure:

wherein R₁ and R₂ are independently C₁-C₁₅ alkyl, C₂-C₁₅ alkenyl,halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15 alkyl), eachof which may be optionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl,C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano, acyloxy,carboxy, or ester;

or

wherein R₁ and R₂ are taken together with the atoms to which they arebound to form a 5-7 membered heterocyclic ring which may be optionallysubstituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl,halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl),aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio,hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester.

In another aspect, the invention provides a method of making a methylenebeta-ketoester monomer comprising:

-   -   a) reacting a beta-ketoester reactant having the structural        formula:

-   -   -   under suitable reaction conditions for sufficient time with            a source of formaldehyde, optionally in the presence of an            acidic or basic catalyst, and optionally in the presence of            an acidic or non-acidic solvent, to form a reaction complex;            and

    -   b) isolating a methylene beta-ketoester monomer from the        reaction complex, wherein the methylene beta-ketoester monomer        has the structural formula:

-   -   -   wherein each instance of R₁ and R₂ are independently C₁-C₁₅            alkyl, C₂-C₁₅ alkenyl, halo-(C₁-C₁₅ alkyl), C₃-C₆            cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,            heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),            heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15            alkyl), each of which may be optionally substituted by            C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl,            halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅            alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅            alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano,            acyloxy, carboxy, or ester;

    -   or        -   wherein R₁ and R₂ are taken together with the atoms to which            they are bound to form a 5-7 membered heterocyclic ring            which may be optionally substituted by C₁₅ alkyl,            halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆            cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl),            aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅            alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy,            or ester.

In certain embodiments, the methods of the invention herein include thestep of isolating the methylene beta-ketoester by:

-   -   i. contacting the reaction complex, or a portion thereof, with        an energy transfer means to produce a vapor phase including the        methylene beta-ketoester monomer; and    -   ii. collecting the methylene beta-ketoester monomer from the        vapor phase.

In other embodiments, the methods of the invention herein includeisolating the methylene beta-ketoester by:

-   -   i. heating the reaction complex, or a portion thereof, to a        temperature between about 130° C. and about 300° C. to produce a        vapor phase including the methylene beta-ketoester monomer; and    -   ii. collecting the methylene beta-ketoester monomer from the        vapor phase.

In still other embodiments, the methods of the invention are performedunder reaction conditions of:

-   -   a) an initiating temperature of between about 60° C. and about        130° C.;    -   b) atmospheric pressure.

In another aspect, the invention provides a method of preparing amethylene beta-ketoester monomer comprising:

-   -   a) reacting a beta-ketoester reactant having the structural        formula:

-   -   -   under suitable reaction conditions for sufficient time with            a source of formaldehyde, optionally in the presence of an            acidic or basic catalyst, and optionally in the presence of            an acidic or non-acidic solvent, to form a reaction complex;

    -   b) contacting the reaction complex, or a portion thereof, with        an energy transfer means at a temperature between about 150° C.        and about 300° C. to provide the reaction complex, or portion        thereof, as a vapor phase; and

    -   c) isolating a methylene beta-ketoester monomer from the        reaction complex or portion thereof, wherein the methylene        beta-ketoester monomer has the structural formula:

-   -   -   wherein each instance of R₁ and R₂ are independently C₁-C₁₅            alkyl, C₂-C₁₅ alkenyl, halo-(C₁-C₁₅ alkyl), C₃-C₆            cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,            heterocyclyl-(C₁-C₁₅alkyl), aryl, aryl-(C1-C15 alkyl),            heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15            alkyl), each of which may be optionally substituted by            C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl,            halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅            alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅            alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano,            acyloxy, carboxy, or ester;

    -   or        -   wherein each instance of R₁ and R₂ are taken together with            the atoms to which they are bound to form a 5-7 membered            heterocyclic ring which may be optionally substituted by            C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl,            halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅            alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅            alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano,            acyloxy, carboxy, or ester.

In another aspect, the invention provides a polymerizable compositioncomprising a methylene beta-ketoester monomer of the invention.

In certain embodiments, the polymerizable composition is capable ofbonding glass to a substrate in a time period of less than about 90seconds, less than about 60 seconds, less than about 30 seconds, or lessthan about 15 seconds.

In certain other embodiments, the polymerizable composition comprising amethylene beta-ketoester monomer further comprises at least one additiveselected from the group consisting of an acidic stabilizer, a freeradical stabilizer, a sequestering agent, a cure accelerator, a rheologymodifier, a plasticizing agent, a thixotropic agents, a natural rubber,a synthetic rubbers, a filler agent and a reinforcing agent.

In another aspect, the invention provides an adhesive product comprisinga methylene beta-ketoester monomer of the invention.

In certain embodiments, the adhesive products have a shelf life of atleast one year.

In another aspect, the invention provides a polymer formed bypolymerization of one or more methylene beta-ketoester monomers or apolymerizable composition thereof.

In certain embodiments, the polymers of the invention are useful as asealant, a coating, a textile fiber, a water-treatment polymer, an inkcarrier, a paint carrier, a packaging film, a molding, a medicalpolymer, a polymer film, a polymer fiber, or a polymer sheet.

In certain other embodiments, the polymers of the invention have repeatunits of the formula:

wherein R and R′ are independently C₁-C₁₅ alkyl, C₂-C₁₅ alkenyl,halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15 alkyl), eachof which may be optionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl,C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano, acyloxy,carboxy, or ester.

In another aspect, the invention provides an oligomeric complex preparedby reacting a beta-ketoester with a source of formaldehyde; optionallyin the presence of heat transfer agent; optionally in the presence of anacidic or basic catalyst; and optionally in the presence of an acidic ornon-acidic solvent. In certain embodiments, the oligomeric complex hasbetween 2 and 12 repeat units having the structural formula:

wherein R and R′ are independently C₁-C₁₅ alkyl, C₂-C₁₅ alkenyl,halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15 alkyl), eachof which may be optionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl,C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano, acyloxy,carboxy, or ester.

In still another aspect, the invention provides a methylenebeta-ketoester monomer prepared according to the methods of theinvention.

The invention may include a step of minimizing the recovery of volatilelatent acid forming impurities. This step may in certain embodimentscomprise (a) adding to the reaction mixture water and an acid having apKa range of −8 to 5; (b) adding to the reaction mixture a stericallyhindered organic acid; or (c) adding to the reaction mixture anon-volatile organic acid, or any combination of (a), (b) or (c). Incertain other embodiments, the step of minimizing the recovery ofvolatile latent acid forming impurities may comprise adding to thereaction mixture water and an acid having a pKa range of −8 to 5.

The methylene beta-ketester monomers may be used to make products,including but not limited to, an adhesive, a coating, a sealant, acomposite, or a surfactant. Such products, in various embodiments, canfurther comprise an acidic stabilizer, a free radical stabilizer, asequestering agent, a cure accelerator, a rheology modifier, aplasticizing agent, a thixotropic agents, a natural rubber, a syntheticrubbers, a filler agent, a reinforcing agent or a combination thereof.

In certain embodiments, the acid stabilizer can have a pKa in the rangeof −15 to 5, or in the range of −15 to 3, or in the range of −15 to 1.

In some embodiments, the acid stabilizer is a volatile acid stabilizerwith a boiling point less than 200° C.

In other embodiments, the acid stabilizer is a volatile acid stabilizerwith a boiling point less than 170° C.

In still other embodiments, the acid stabilizer is a volatile acidstabilizer with a boiling point less than 130° C.

In other embodiments, the acid stabilizer can be an acidic gas, such as,for example, SO₂ or BF₃.

In some embodiments, the acid stabilizer can be present in aconcentration of about 0.1 ppm to about 100 ppm, or from about 0.1 ppmto about 50 ppm, or from about 0.1 ppm to about 25 ppm, or from about0.1 ppm to about 15 ppm.

The methylene beta-ketoester monomers and/or products may include a freeradical stabilizer, such as a phenolic free radical stabilizer, and maybe present in a concentration of about 0.1 ppm to about 10000 ppm, orfrom about 0.1 ppm to about 3000 ppm, or from about 0.1 ppm to about1500 ppm, or from about 0.1 ppm to about 1000 ppm, or from about 0.1 ppmto about 300 ppm, or from about 0.1 ppm to about 150 ppm.

In yet another embodiment, the present invention relates to an adhesiveproduct or composition comprising a methylene beta-ketoester monomerprepared according to a method of the invention and which is stable forat least one year. In other embodiments, the monomer and/or thepolymerizable compositions (e.g., the adhesive products formed by amethod of the invention), are compositions wherein the level of ketalsis less than about 100 ppm, or less than about 50 ppm, or less thanabout 25 ppm, or less than about 10 ppm, or less than about 5 ppm, oreven less than about 0.1 ppm, or less.

In still other embodiments, the monomer and/or the polymerizablecomposition (e.g., the adhesive products formed by a method of theinvention), have a purity such that the level of other latentacid-forming impurities is less than about 100 ppm, or less than about50 ppm, or less than about 25 ppm, or less than about 10 ppm, or lessthan about 5 ppm, or even less than about 0.1 ppm, or less.

Another aspect of the disclosure is directed at a process comprising thesteps of: mixing one or more monomers (including a first monomer that isa 1,1-disubstituted alkene compound (e.g., a methylene beta-ketoestermonomer)) and a solvent; adding an activator; reacting the activatorwith one of the one or more monomers (e.g., with the first monomer) forinitiating the anionic polymerization of the one or more monomers; andanionically polymerizing the one or more monomers to form a polymerhaving a weight average molecular weight and/or a number averagemolecular weight of about 2000 daltons or more, the polymer includingthe first monomer, wherein the first monomer is provided as a highpurity monomer having a purity of about 95 weight percent or more.Preferably the high purity monomer has a purity of about 97 weightpercent, even more preferably about 99 weight percent. For example, thehigh purity monomer may include the 1,1-disubstituted alkene compoundhaving an alkene group and the total concentration of any analogouscompound (i.e., impurity compound) having the alkene group replaced byhydroxyalkyl group is about 3 mole percent or less (preferably about 1mole percent or less, even more preferably about 0.1 mole percent orless, and most preferably about 0.01 mole percent or less), based on thetotal moles of the 1,1-disubstituted alkene compound. The 1,1,disubstituted alkene compound may be a methylene beta-ketoester monomer.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those having ordinary skill in the art to which the subjectinvention pertains will more readily understand how to make and use theinvention as described herein, preferred embodiments thereof will bedescribed in detail below, with reference to the drawings, wherein:

FIGS. 1 and 2 depict NMR spectra demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of ethyl4,4-dimethyl-3-oxopentanoate and formaldehyde.

FIGS. 3 and 4 depict NMR spectra demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of ethyl3-oxo-3-phenylpropanoate with formaldehyde.

FIG. 5 depicts an NMR spectrum demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of ethyl3-oxo-hexanoate with formaldehyde.

FIG. 6 depicts an NMR spectrum demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of ethyl3-oxobutanoate with formaldehyde.

FIG. 7 depicts an NMR spectrum demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of methyl3-oxobuanoate with formaldehyde.

FIG. 8 depicts an NMR spectrum demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of ethyl4-methyl-3-oxopentanoate with formaldehyde.

FIG. 9 depicts an NMR spectrum demonstrating evidence of a methylenebeta-ketoester reaction product formed by the reaction of ethyl3-oxopenanoate with formaldehyde.

DESCRIPTION OF THE INVENTION Overview

The present invention provides new and nonobvious improvements andmodifications in the use and application of the Knoevenagel reaction inorder to produce methylene beta-ketoester monomers:

Modified Knoevenagel Reaction

While the above reaction scheme shows a direct condensation reaction, ithas been discovered that an intermediary species (oligomeric complex)may be formed in certain instances. The oligomeric complex may then becracked to yield the monomer product. As those having skill in the artwill appreciate, the reaction scheme may also yield side reactions andundesired products, and unreacted starting material from which themethylene beta-ketoester monomers are subsequently isolated.

Definitions

Unless defined otherwise, all technical and scientific terms used hereinhave the meaning commonly understood by a person skilled in the art towhich this invention belongs. The following references provide one ofskill with a general definition of many of the terms used in thisinvention: Singleton et al., Dictionary of Microbiology and MolecularBiology (2nd ed. 1994); The Cambridge Dictionary of Science andTechnology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R.Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, TheHarper Collins Dictionary of Biology (1991). As used herein, thefollowing terms have the meanings ascribed to them below, unlessspecified otherwise.

As used herein, the term “methylene beta-ketoester monomer” refers to acompound having the core formula —C(O)—C(CH₂)—C(O)O—.

As used here, the term “beta-ketoester” refers to a compound having thecore formula —C(O)—CH₂—C(O)O—.

As used herein, the term “monofunctional” refers to a methylenebeta-ketoester or a beta-ketoester having only one core formula.

As used herein, the term “difunctional” refers to a methylenebeta-ketoester or a beta-ketoester having two core formulas.

As used herein, the term “multifunctional” refers to a methylenebeta-ketoester or a beta-ketoester having two or more core formulas.Thus the term multifunctional encompasses the term difunctional.

As used herein, the term “reaction complex” refers to the materialswhich result after reacting a beta-ketoester starting material with asource of formaldehyde. Such reaction complexes may comprise, withoutlimitation, methylene beta-ketoester monomers, oligomeric complexes,irreversible complex impurities, starting materials, or latentacid-forming impurities.

As used herein, the term “reaction vessel” refers to any container inwhich the reactants, solvents, catalysts or other materials may becombined for reaction. Such reaction vessels can be made of any materialknown to one of skill in the art such as metal, ceramic or glass.

As used herein, the term “vapor phase” refers to a gaseous phase whichmay comprise, without limitation, vaporized methylene beta-ketoestermonomer, vaporized starting materials; vaporized solvents, or vaporizedimpurities.

As used herein, the term “recovering” or “obtaining” or “isolating”refers to the removal of the monomer from the reaction mixture, vaporphase, or condensed vapor phase by one of the methods described herein,although the desired product may not be in a purified form. The term“crack” is also used to indicate depolymerization of an oligomericcomplex. The desired methylene beta-ketoester monomer may be obtained by“cracking” an oligomeric complex found in the reaction complex.

As used herein, the term “sterically hindered” refers to a compound inwhich the size of groups within the molecule prevents chemical reactionsthat are observed in related smaller molecules.

As used herein, the terms “volatile” and “non-volatile” refers to acompound which is capable of evaporating readily at normal temperaturesand pressures, in the case of volatile; or which is not capable ofevaporating readily at normal temperatures and pressures, in the case ofnon-volatile.

As used herein, the term “energy transfer means” refers to a means whichis capable of volatizing a reaction complex, usually by, but not limitedto, rapidly heating the reaction complex to temperatures from about 150°C. to about 300° C. Such energy transfer means include, but are notlimited to, heat transfer agents, heat transfer surfaces, lasers, andsources of radiation.

As used herein, the term “heat transfer agent” refers to a materialwhich is capable of achieving a high temperature and transferring thattemperature to a reaction mixture. Such heat transfer agents aretypically able to reach temperatures from about 150° C. to about 300° C.and include, but are note limited to silica, silicone oil, mineral oil,a petroleum based heat transfer oil or a synthetic chemical based heattransfer oil. In certain embodiments, the heat transfer agent can bepre-formed reaction complex.

As used herein the term “pre-formed reaction complex” refers to areaction complex as defined herein which is prepared by reacting step(a) as described herein in advance of the vaporization step (b). Suchpre-formed reaction complexes can be formed up to a year, up to sixmonths, up to 3 months, up to 1 month, up to 2 weeks, up to 1 week, upto 3 days, or up to 1 day in advance of the vaporization step (b). Insuch instances, the vaporization step (b) is performed on a newlyprepared reaction complex. In certain aspects the pre-formed reactioncomplex can refer to an oligomeric complex as defined herein.

As used herein the term “substantial absence” as in “substantial absenceof acidic solvent” refers to a reaction mixture comprising less than 1%by weight of the particular component as compared to the total reactionmixture. In certain embodiments, a “substantial absence” refers to lessthan 0.7%, less than 0.5%, less than 0.4% m less than 0.3%, less than0.2% or less than 0.1% by weight of the of the particular component ascompared to the total reaction mixture. In certain other embodiments, a“substantial absence” refers to less than 1.0%, less than 0.7%, lessthan 0.5%, less than 0.4% m less than 0.3%, less than 0.2% or less than0.1% by volume of the of the particular component as compared to thetotal reaction mixture.

As used herein, the term “stabilized,” e.g., in the context of“stabilized” molecules of the invention or compositions comprising same,refers to the tendency of the molecules of the invention (or theircompositions) to substantially not polymerize with time, tosubstantially not harden, form a gel, thicken, or otherwise increase inviscosity with time, and/or to substantially show minimal loss in curespeed (i.e., cure speed is maintained) with time.

As used herein, the term “shelf-life,” e.g., as in the context of themolecules of the invention having an improved “shelf-life,” refers tothe molecules of the invention which are stabilized for a given periodof time, e.g., 1 month, 6 months, or even 1 year or more.

As used herein, the term “latent acid-forming impurities” or “latentacid-forming impurity” refers to any impurity that, if present alongwith the recovered monomer, will with time be converted to an acid. Theacid formed from these impurities tends to result in overstabilizationof the monomer (e.g., methylene beta-ketoester monomer or methylenemalonate monomer), thereby reducing the overall quality and reactivityof the monomer.

As used herein, the term “ketal” refers to molecule having a ketalfunctionality; i.e. a or molecule containing a carbon bonded to two —ORgroups, where O is oxygen and R represents any alkyl group.

Description of Exemplary Embodiments

Methylene beta-ketoester monomers in accordance with the presentinvention may be made by a modified Knoevenagel condensation reaction ofa beta-ketoester with formaldehyde under suitable reaction conditions.The general reaction scheme is provided below.

Modified Knoevenagel Reaction Methylene Beta-Ketoester Monomers

In one aspect, the invention provides a methylene beta-ketoester monomerhaving the structural formula:

wherein each instance of R₁ and R₂ are independently C₁-C₁₅ alkyl,C₂-C₁₅ alkenyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl,aryl-(C1-C15 alkyl), heteroaryl or hetero aryl —(C₁-C₁₅ alkyl), oralkoxy —(C1-15 alkyl), each of which may be optionally substituted byC₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl(C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio, hydroxyl,nitro, azido, cyano, acyloxy, carboxy, or ester;orwherein R₁ and R₂ are taken together with the atoms to which they arebound to form a 5-7 membered heterocyclic ring which may be optionallysubstituted by C₁-C₁₅ alkyl, halo-(C₁-C₁5 alkyl), C3-C6 cycloalkyl,halo-(C3-C6 cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl),aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio,hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester.

In certain embodiments, the invention provides a methylenebeta-ketoester monomer having the structural formula:

wherein each instance of R₁ and R₂ are independently C₁-C₆ alkyl,halo-(C₁-C₆ alkyl), C₃-C₆ cycloalkyl, heterocyclyl, heterocyclyl-(C₁-C₆alkyl), aryl, aryl-(C1-C6 alkyl), heteroaryl or heteroaryl-(C₁-C₆alkyl), each of which may be optionally substituted by halo or C₁-C₆alkoxy.

In other embodiments, the invention provides a methylene beta-ketoestermonomer having the structural formula:

wherein each instance of R₁ and R₂ are independently C₁-C₆ alkyl oraryl.

Reactants

The reaction for making methylene beta-ketoester monomers of theinvention includes at least two basic reactants: a beta-ketoesterprecursor and a source of formaldehyde.

The methylene beta-ketoester precursors in accordance with exemplaryembodiments disclosed herein include beta-ketoesters able to undergo acondensation reaction at the alpha carbon. Beta-ketoester precursorsinclude, but are not limited to, molecules having the structuralformula:

wherein each instance of R₁ and R₂ are independently C₁-C₁₅ alkyl,C₂-C₁₅ alkenyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅alkyl), aryl,aryl-(C1-C15 alkyl), heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy—(C1-15 alkyl), each of which may be optionally substituted by C₁-C₁₅alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl),heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido,cyano, acyloxy, carboxy, or ester;

or

wherein R₁ and R₂ are taken together with the atoms to which they arebound to form a 5-7 membered heterocyclic ring which may be optionallysubstituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl,halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl),aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio,hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester.

In certain other embodiments, the present invention contemplates thefollowing specifically identified beta-ketoester precursors: ethyl4,4-dimethyl-3-oxopentanoate, ethyl 3-oxo-3-phenylpropanoate, ethyl3-oxohexanoate, ethyl 3-oxobutanoate, methyl 3-oxobuanoate, ethyl4-methyl-3-oxopentanoate, and ethyl 3-oxopenanoate among others.

The beta-ketoester precursor may be derived or obtained from any source,including any commercial source, derived from nature, other compounds,synthesized by other processes, etc. In certain embodiments, thebeta-ketoester precursors are obtained from “green” sources. Forexample, the beta-ketoester precursors can be derived from biologicalsources, such as via fermentation production systems wherebymicroorganisms generate the beta-ketoester precursors is directmetabolic by-products of fermentation or whereby the microorganismsgenerate metabolic by-products of fermentation that can be thenconverted inexpensively to the desired beta-ketoester precursors. Thesefermentation production systems are well-known in the art and mayutilize either or both microorganisms derived from nature or engineeredmicroorganisms that are specifically designed to produce the desiredbeta-ketoester precursors products, e.g., recombinant or engineeredEscherichia coli. The beta-ketoester precursor is reacted with a sourceof formaldehyde. The methods of the invention also contemplate anysuitable source of formaldehyde. For example, the formaldehyde may besynthesized, derived from another chemical species (e.g.,paraformaldehyde), or obtained from nature or from some other suitablesource. In certain embodiments, the formaldehyde is introduced in theform of a gas. Commercial sources of formaldehyde and paraformaldehydeare readily available, which may include, for example, trioxane andformalin (e.g., aqueous formaldehyde). The source of formaldehyde may beparaformaldehyde, formalin or gaseous formaldehyde. In certainembodiments, the formaldehyde is obtained from paraformaldehyde. In anexemplary embodiment, the source of formaldehyde is paraformaldehydethat is thermally degraded to formaldehyde in the reaction vessel. It isenvisioned that other means of providing formaldehyde to the reactionvessel may be utilized, for example, a stream of gaseous formaldehyde.

Catalysts

In an certain embodiments, the methods of preparing the methylenebeta-ketoester takes place in the presence of a suitable catalyst.However, it is envisioned that certain reactions may not required thepresence of a catalyst.

In certain embodiments, the catalysts that may be used include, but arenot limited to, basic catalysts such as potassium acetate, sodiumacetate, zinc acetate, zinc diacetate dihydrate, aluminum acetate,calcium acetate, magnesium acetate, magnesium oxide, copper acetate,lithium acetate, aluminum oxide, or zinc oxide.

In further embodiments, the catalysts include, but are not limited to,acidic catalysts such as paratoluene sulfonic acid, dodecylbenzenesulfonic acid, boron trifluoride, zinc perchlorate, sulfated zirconiumoxide, sulfated titanium oxide, lithium chloride, boron trifluorideetherate, ferric sulfate, zirconium oxychloride, cupric chloride,titanium tetrachloride, or zinc chloride.

Still other exemplary catalysts are heterogeneous catalysts. Still otherexemplary catalysts are enzyme catalysts. An exemplary enzyme isNovozym® 435 available from Novozyme. Novozym 435 is an immobilizedgranulate, non-specific lipase particularly useful for ester production.Neutral catalysts can also include silica and other insolublesurface-active agents.

In still further embodiments, amphoteric catalysts can include, but arenot limited to, aluminum oxide, aluminum acetate, zinc acetate,magnesium acetate, and zinc oxide.

In still other embodiments, the present inventors have surprisingly andunexpectedly found that no catalyst is required to conduct the synthesisreaction of the invention. Specifically, in this embodiment, thereaction can be conducted with all of the reactants added to thereaction vessel at the start of the reaction prior to adding heat. Thesource of formaldehyde in this embodiment is preferably solidparaformaldehyde, and is added along with the other reactants, includingthe malonic ester, prior to adding heat. This reaction surprisingly canbe run rapidly and in a continuous mode and unexpectedly avoids theformation of or substantially minimizes the formation of deleteriousside products, unwanted polymerization complexes and degradation of themonomer products.

Solvents

The present invention contemplates that the synthesis reaction includean acidic or non-acidic solvent, or optionally no solvent at all.

Non-acidic solvents can include, but are not limited to,tetrahydrofuran, chloroform, dichloromethane, toluene, heptane, ethylacetate, n-butyl acetate, dibutyl ether and hexane.

Acidic solvents can include, but are not limited to acetic acid andpropionic acid.

In certain embodiments, the acidic solvent is added just prior torecovery.

In certain other embodiment, optionally no solvent is needed. Thiszero-solvent approach will not only decrease the overall cost ofproduction but will also help to lessen any negative impact on theenvironment caused by the methods of the invention, i.e., provides anenvironmentally-friendly approach to the synthesis of2-methylene-1,3-disubstituted-propane-1,3-diones. An advantage of thiscondition is the avoidance or minimization of the formation ofimpurities, e.g., ketals and other latent acid-forming species.

In still other embodiments, the present inventors have surprisingly andunexpectedly found that the synthesis reaction of the invention may beconducted in the absence of both a solvent and a catalyst. Specifically,in this embodiment, the reaction can be conducted with all of thereactants added to the reaction vessel at the start of the reactionprior to adding heat and in the absence of a solvent. The source offormaldehyde in this embodiment is preferably solid paraformaldehyde,and is added along with the other reactants, including the malonicester, prior to adding heat. This reaction surprisingly can be runrapidly and in a continuous mode and unexpectedly avoids the formationof or substantially minimizes the formation of deleterious sideproducts, unwanted polymerization complexes and degradation of themonomer products.

The formation of the monomer may be carried out with a step ofminimizing the recovery of volatile latent acid forming impurities fromthe reaction complex, such as ketals, which can co-distill with the1,1-disubstituted alkene monomer (e.g., methylene beta-ketoester monomeror methylene malonate monomer) products and then revert to their acidicform with time. Once in their acidic form, the acidic environmentincreases, which further blocks or weakens the reactivity of the1,1-disubstituted alkene monomer as they are stabilized againstpolymerization. This can be particularly relevant to the use of1,1-disubstituted alkene monomers in the context of adhesives, where theincreased acid content with time due to the presence of such volatilelatent acid forming impurities can impinge on the overall reactivity andcure speed, etc., of the monomer products.

Although the invention may employ an improved Knovenagel reaction withformaldehyde to synthesize 1,1-disubstituted alkene monomer (e.g.,methylene beta-ketoester monomer or methylene malonate monomer), thepresent invention should not be limited as such. The present inventorshave generally recognized it is believed for the first time generalconcept that the performance and overall quality of 1,1-disubstitutedalkene monomer (e.g., methylene beta-ketoester monomer or methylenemalonate monomer) is particularly sensitive to the presence of unwantedalternative and deleterious side products and unwanted monomerdegradation and/or consumption is widely applicable to any type ofsynthesis that can be used to generate 1,1-disubstituted alkene monomer.Prior to the present invention, the significance and nature of thesetypes of impurities and their effects on the performance and quality ofmethylene malonates was not previously contemplated. Thus, for the firsttime, the present invention provides a viable approach to producing1,1-disubstituted alkene monomer(s) that can be utilized as the basisfor viable consumer and industrial monomer-based (e.g., adhesives) andpolymer-based (e.g., fibers) products.

The 1,1-disubstituted alkene compound (e.g., the methylenebeta-ketoester compound) preferably is prepared using a method whichresults in a sufficiently high purity so that it can be polymerized. Thepurity of the 1,1-disubstituted alkene compound(e.g., the methylenebeta-ketoester compound) may be sufficiently high so that 70 molepercent or more, preferably 80 mole percent or more, more preferably 90mole percent or more, even more preferably 95 mole percent or more, andmost preferably 99 mole percent or more of the 1,1-disubstituted alkenecompound is converted to polymer during a polymerization process. Thepurity of the 1,1-disubstituted alkene compound (e.g, the methylenebeta-ketoester compound) preferably is about 85 mole percent or more,more preferably about 90 mole percent or more, even more preferablyabout 93 mole percent or more, even more preferably about 95 molepercent or more, even more preferably about 97 mole percent or more, andmost preferably about 99 mole percent or more, based on the total weightof the 1,1-disubstituted alkene compound. If the 1,1-disubstitute alkenecompound includes impurities, preferably about 40 mole percent or more,more preferably about 50 mole percent or more of the impurity moleculesare the analogous 1,1-disubstited alkane compound. The concentration ofany impurities having a dioxane group preferably is about 2 mole percentor less, more preferably about 1 mole percent or less, even morepreferably about 0.2 mole percent or less, and most preferably about0.05 mole percent or less, based on the total weight of the1,1-disubstituted alkene compound. The total concentration of anyimpurity having the alkene group replaced by an analogous hydroxyalkylgroup (e.g., by a Michael addition of the alkene with water), preferablyis about 3 mole percent or less, more preferably about 1 mole percent orless, even more preferably about 0.1 mole percent or less, and mostpreferably about 0.01 mole percent or less, based on the total moles inthe 1,1-disubstituted alkene compound. Preferred 1,1-disubstitutedalkene compounds are prepared by a process including one or more (e.g.,two or more) steps of distilling a reaction product or an intermediatereaction product (e.g., a reaction product or intermediate reactionproduct of a source of formaldehyde and a malonic acid ester).

The 1,1-disubstituted alkene compound (e.g., the methylenebeta-ketoester compound) may include a monomer produced according to theteachings of U.S. Pat. No. 8,609,885 (Malofsky et al.) incorporatedherein by reference in its entirety. Other examples of monomers whichmay be employed include the monomers taught in International PatentApplication Publication Nos. WO2013/066629 and WO 2013/059473, bothincorporated herein by reference.

Stabilization

Certain embodiments of the present invention provide monomers that areamenable to anionic polymerization. Therefore, to prevent unwantedpolymerization and extend shelf life, certain exemplary embodimentsinclude suitable acidic stabilizers, for example, trifluoromethanesulfonic acid, maleic acid, methane sulfonic acid, difluoro acetic acid,trichloroacetic acid, phosphoric acid, dichloroacetic acid,chlorodifluoro or like acid. Acidic stabilizers can include any materialwhich can be added to the monomer or polymer compositions to extendshelf-life, e.g., by up to, for example, 1 year or more. Such acidicstabilizers may have a pKa in the range of, for example, between about−15 to about 5, or between about −15 to about 3, or between about −15 toabout 1, or between −2 to about between about −2 to about 2, or betweenabout 2 to about 5, or between about 3 to about 5.

Reaction Conditions

In certain embodiments of the present invention, the starting precursoris reacted with paraformaldehyde in the presence of a catalyst (e.g.,zinc acetate dehydrate) at 60° C.-130° C. (e.g., 100° C.) for at leastabout 30 minutes. The resulting intermediate material (e.g., oligomericcomplex) is then thermally depolymerized to the vinyl containing productby addition to a hot surface set from 150° C. to 270° C. The resultingcrude monomer is then purified, for example by distillation, fractionaldistillation or other separation methods.

For a typical lab scale reaction: a 3-neck 250 mL round bottom reactionflask was equipped with an overhead stirrer, a heating mantle, and atemperature probe connected to a temperature controller. The reactionflask was adequately vented to the back of the hood to reduce thepossibility of pressure build-up. The beta-ketoester (precursor),paraformaldehyde (1.8 equiv) and zinc acetate (0.001 equiv) were addedto the reaction flask. The contents of the flask were mixed forapproximately 2 minutes prior to the application of heat. After theinitial mixing period the temperature controller was set to 100° C. Theheterogeneous reaction mixture was allowed to heat with the temperaturefor dissolution and onset of exotherm being noted. Once a rapid increasein temperature was observed, heating was discontinued. Once the exothermsubsided, the heating mantle was immediately removed and the reactionmixture (herein “reaction complex”) was allowed to cool to roomtemperature to afford the oligomeric mixture.

To isolate the methylene beta-ketoester monomer from the reactioncomplex, a 4-neck suitable round bottom flask was equipped with amechanical stirrer, heating mantle, a thermocouple connected to atemperature controller, an addition funnel, a Claisen adapter, and avacuum adapter connected to a receiver one-neck round bottom flask whichwas placed in an ice-bath. The system was evacuated to low pressure(1-250 mmHg). The oligomeric mixture was added to the addition funnel.The reaction flask was then applied via the connected heating mantle to150-270° C. Once the temperature inside the flask reached the desiredrange, a drop-wise addition of the oligomer (reaction complex) toreaction flask was started. The addition rate was maintained so that theset temperature was maintained in the desired range. After the additionwas complete, the heating mantle was turned off and the system wasallowed to cool to room temperature, at this point the system was openedto atmospheric pressure. An aliquot was then taken for analysis and theremaining cracked distillate was either distilled further via fractionaldistillation to improve purity or placed in a refrigerator.

This general reaction scheme was utilized to provide the examplesprovided herein. Due to the wide variety of example obtained, it isenvisioned that this general reaction scheme can be utilized to providea wide array of methylene beta-ketoester monomers as set forth herein.Further, it is envisioned that modifications can be made to this generalreaction scheme in order to improve efficiencies and purity of theproduct obtained.

Methods of Synthesis

In another aspect, the invention provides a method of preparingmethylene beta-ketoester monomers according to the reaction schemedisclosed herein.

In certain embodiments, the method for preparing the methylenebeta-ketoester monomers comprises:

-   -   a) reacting a beta-ketoester reactant having the structural        formula:

-   -   -   under suitable reaction conditions for sufficient time with            a source of formaldehyde, optionally in the presence of an            acidic or basic catalyst, and optionally in the presence of            an acidic or non-acidic solvent, to form a reaction complex;            and

    -   b) isolating a methylene beta-ketoester monomer from the        reaction complex, wherein the methylene beta-ketoester monomer        has the structural formula:

wherein R₁ and R₂ are defined above.

In certain embodiments, the reaction may be initiated at temperaturesbetween about 60° C. to about 130° C., at atmospheric pressure. It iscontemplated that the reaction conditions may be modified depending onthe source of formaldehyde. For example, when paraformaldehyde isutilized within the reaction vessel, the initial temperature must behigh enough to make free formaldehyde available for the reaction. Ifanother source of formaldehyde is utilized, those having skill in theart will appreciate that the reaction conditions may be modifiedaccordingly. Exemplary sources include paraformaldehyde, formalin,trioxane, gaseous formaldehyde, or any reaction or process in whichformaldehyde is liberated.

In other embodiments, the methylene beta-ketoester monomer may beisolated from the reaction complex by contacting the reaction complex,or a portion thereof, with an energy transfer means to produce a vaporphase including the methylene beta-ketoester monomer; and collecting themethylene beta-ketoester monomer from the vapor phase.

In still other embodiments, the methylene beta-ketoester monomer may beisolated from the reaction complex immediately, or the reaction complexmay be stored, preferably refrigerated, until a later time. In anexemplary embodiment, the reaction complex is not acid stabilized priorto isolating the methylene beta-ketoester monomer.

In other embodiments, the reaction complex, or a portion thereof, may beheated to a vapor phase and condensed in order to isolate the methylenebeta-ketoester monomer. The reaction complex may be heated to atemperature between about 130° C. and about 300° C.

In still other embodiments, the reaction complex, or a portion thereof,may come in contact with an energy transfer means in order to facilitateisolation of the monomer. In an exemplary embodiment, the reactioncomplex, or portion thereof, may be vaporized in a very short time, forexample less than 15 minutes, preferably less than 1 minute, morepreferably less than 30 seconds, and less than 1 second. Certainexemplary embodiments contemplate vaporizing the reaction complex in acontinuous manner as it is formed during the reaction step.

Exemplary energy transfer means include a heat transfer agent, a heatexchanger, a laser, microwave energy, sonic energy, electromagneticenergy, and a source of radiation, or any combination thereof. Theenergy transfer means operates to quickly vaporize the reaction complex(or portion thereof) to permit isolation of the monomer product. Forexample, an oligomeric complex may be formed, and the energy transfermeans is utilized to “crack” or depolymerize the oligomer to allowisolation of the monomer. In certain embodiments, the oligomeric complexmay include oligomers of 2-12 units able to provide monomer product uponcrack.

In certain exemplary embodiments, the heat transfer agent is a heatedinert gas, one or more metal beads, one or more glass beads, one or moreporcelain beads, sand, silica, silicone oil, mineral oil, a petroleumbased heat transfer oil, a synthetic chemical based heat transfer oil,or a pre-formed portion of the reaction complex.

In certain other embodiments, the heat exchanger is a shell and tubeheat exchanger, a plate heat exchanger, and adiabatic wheel heatexchanger, a finned pipe heat exchanger, a plate fin heat exchanger, ora scraped surface heat exchanger.

In still other embodiments, the vapor phase of the reaction complex iscondensed, and the condensate is subject to one or more furtherseparation processes. For example, the separation process may includeany of simple distillation, fractional distillation, flash distillation,steam distillation, vacuum distillation, short path distillation,thin-film distillation, reactive distillation, pervaporation, extractivedistillation, flash evaporation, rotary evaporation, liquid/liquidextraction, centrifuging, or any combination thereof, and othertechniques known to those having skill in the art.

Compositions

The methylene beta-ketoester monomers of the invention can beincorporated into any number of compositions and products including butnot limited to reactive monomer-based compositions, reactiveoligomer-based compositions and reactive polymer-based compositions.

Exemplary compositions can be analyzed by placing a drop of a monomercomposition on a substrate (for example a glass slide or 4″×1″polycarbonate sample). Another glass slide or piece of polycarbonate ispressed on top over the monomer-covered area. The time is thenimmediately recorded from pressing the top-slide till the two slides arebonded tightly. In such embodiments, the exemplary composition iscapable of bonding glass to a substrate in less than about 90 seconds,less than about 60 seconds, less than about 30 seconds or less thanabout 15 seconds. Similarly, the exemplary composition is capable ofbonding polycarbonate to a substrate in less than about 90 seconds, lessthan about 60 seconds, less than about 45 seconds or less than about 30seconds.

Alternatively, exemplary compositions can be analyzed by mixing 0.5 mlof monomer with 0.3 ml of 3% tertiary butyl ammonium fluoride (TBAF) inDibutyl Phthalate solution. The time is recorded from adding the TBAFsolution till the mixture become solid with vigorous stirring or mixing.In such embodiments, said composition solidifies upon addition of 3%tertiary butyl ammonium fluoride (TBAF) in Dibutyl Phthalate solution inless than about 15 seconds, less than about 10 seconds, or less thanabout 7 seconds.

Alternatively still, the exemplary compositions can be analyzed byplacing 0.5 ml of monomer into a test tube and cap with a cork stopperand keeping the test tubes containing monomers at 25° C., or in ovens at55° C. or 82° C. In each case the storage stability test is performed atatmospheric pressure. Time is recorded when the monomer became a gel orsolid. In such embodiments, said composition remains stable at 25° C.and at atmospheric pressure for more than 10 days, more than 15 days,more than 20 days, more than 25 days or more than 30 days. Similarly,said composition remains stable at 82° C. and at atmospheric pressurefor more than about 2 hours, more than about 3 hours, or more than about4 hours.

Exemplary compositions include, but are not limited to an adhesive, acoating, a sealant, a composite, or a surfactant.

Additionally polymer products include, but are not limited to, asealant, a thermal barrier coating, a textile fiber, a water-treatmentpolymer, an ink carrier, a paint carrier, a packaging film, a molding, amedical polymer, a polymer film, a polymer fiber or a polymer sheet.

In each case, the exemplary compositions may be formulated to includeone or more materials to extend the shelf-life as well as control theonset of cure of the materials. In certain embodiments, the compositionsare formulated such that the composition is stable for at least 1 month,or for at least 2 months, or for at least 3 months, or for at least 4months, or for at least 5 months, or for at least 5-10 months, or for atleast 10-20 months, or for at least 20-30 months. Preferably, theadhesive composition comprising the methylene beta-ketoester monomers orother commercial compositions or products, are stable for at least oneyear.

Such formulation materials include acidic stabilizer, volatile acidstabilizers, acidic gases, free radical stabilizers, sequesteringagents, cure accelerators and rheology modifiers.

Exemplary embodiments contemplate any suitable acidic stabilizer knownin the art, including, for example, trifluoromethane sulfonic acid,maleic acid, methane sulfonic acid, difluoro acetic acid,trichloroacetic acid, phosphoric acid, dichloroacetic acid,chlorodifluoro or like acid. Acidic stabilizers can include any materialwhich can be added to the monomer or polymer compositions to extendshelf-life, e.g., by up to, for example, 1 year or more. Such acidicstabilizers may have a pKa in the range of, for example, between about−15 to about 5, or between about −15 to about 3, or between about −15 toabout 1, or between −2 to about between about −2 to about 2, or betweenabout 2 to about 5, or between about 3 to about 5.

Volatile acid stabilizers include any material which can be added to themonomer or polymer compositions to extend shelf-life and stabilize thevapor phase above the composition upon storage, e.g., acidic gases. Suchvolatile acid stabilizers may have a boiling point, for example, lessthan about 200° C.; less than about 170° C.; or less than about 130° C.

Acidic gases include any gaseous material which can be added to themonomer or polymer compositions to extend shelf-life and stabilize thevapor phase above the composition upon storage. Such acid gases caninclude, but are not limited to, SO₂ or BF₃.

For each of these acidic stabilizing materials, such acidic stabilizercan be present in a concentration of about 0.1 ppm to about 100 ppm;about 0.1 ppm to about 25 ppm; or about 0.1 ppm to about 15 ppm.

Free radical stabilizers can include any material capable of stabilizingor inhibiting free radical polymerization of the material upon standing.In one embodiment, the free radical stabilizers are phenolic freeradical stabilizers such as, HQ (hydroquinone), MEHQ(methyl-hydroquinone), BHT (butylated hydroxtoluene) and BHA (butylatedhydroxyanisole). In certain embodiments, the free radical stabilizersare present in a concentration of 0.1 ppm to 10,000 ppm; 0.1 ppm to 3000ppm; or 0.1 ppm to 1500 ppm. In certain other embodiments, particularlywhere a free radical or ultraviolet cure will be utilized, the freeradical stabilizers are present in a concentration of 0.1 ppm to 1000ppm; 0.1 ppm to 300 ppm; or 0.1 ppm to 150 ppm.

Sequestering agents include any material capable of enhancing thebonding of materials containing acid salts such as paper or wood. Suchsequestering agents include, but are not limited to crown ethers, silylcrowns, calixarenes and polyethylene glycols. Sequestering agents alsoenhance the utility of surface accelerators that are acid salts appliedto surfaces to control the rate of cure of the materials.

Cure accelerators include any material capable of speeding the rate ofcure of the methylene beta-ketoester monomers. Cure accelerators alsoinclude any material capable of speeding the cure through volume of theapplied composition. Such cure accelerators include but are not limitedto sodium or potassium acetate; acrylic, maleic or other acid salts ofsodium, potassium lithium copper and cobalt; salts such as tetrabutylammonium fluoride, chloride, or hydroxide; or chemically basic materialssuch as amines and amides, or salts of polymer bond acids, benzoatesalts, 2,4-pentanedionate salts, sorbate salts, or propionate salts.Such cure accelerators can be added directly to the exemplarycompositions or applied to the material to be bonded prior to additionof the composition.

Rheology modifiers include any material which can modify the viscosityof the exemplary compositions as well as thixotropic properties forgreater utility in certain applications. Rheology modifiers include, butare not limited to, hydroxyethylcellulose, ethyl hydroxyethylcellulose,methyl cellulose, polymeric thickeners, pyrogenic silica or acombination thereof.

In certain embodiments, the exemplary compositions may includetougheners. Such tougheners include, but are not limited to, acrylicrubbers; polyester urethanes; ethylene-vinyl acetates; fluorinatedrubbers; isoprene-acrylonitrile polymers; chlorosulfonatedpolyethylenes; homopolymers of polyvinyl acetate; and reaction productsof the combination of ethylene, methyl acrylate and monomers havingcarboxylic acid cure sites, which once formed are then substantiallyfree of processing aids and anti-oxidants; and combinations thereof. Incertain embodiments, the tougheners include those disclosed in U.S. Pat.No. 4,440,910 (O'Connor), directed to rubber toughened cyanoacrylatecompositions through the use of certain organic polymers as tougheningadditives that are elastomeric, i.e., rubbery, in nature, such asacrylic rubbers; polyester urethanes; ethylene-vinyl acetates;fluorinated rubbers; isoprene-acrylonitrile polymers; chlorosulfonatedpolyethylenes; and homopolymers of polyvinyl acetate. In certainembodiments, the toughener is an elastomeric polymer which is acopolymer of methyl acrylate and ethylene, manufactured by DuPont, underthe name of VAMAC, such as VAMAC N123 and VAMAC B-124. VAMAC N123 andVAMAC B-124 are reported by DuPont to be a master batch ofethylene/acrylic elastomer. In other embodiments, the toughener may bethe DuPont materials called VAMAC B-124, N123., VAMAC G, VAMAC VMX 1012or VCD 6200. In other instances, the toughener may be a rubbertoughening component having (a) reaction products of the combination ofethylene, methyl acrylate and monomers having carboxylic acid curesites, (b) dipolymers of ethylene and methyl acrylate, and combinationsof (a) and (b), which once the reaction products and/or dipolymers areformed are then substantially free of processing aids, such as therelease agents octadecyl amine (reported by DuPont to be availablecommercially from Akzo Nobel under the tradename ARMEEN 18D), complexorganic phosphate esters (reported by DuPont to be availablecommercially from R.T. Vanderbilt Co., Inc. under the tradename VANFREVAM), stearic acid and/or polyethylene glycol ether wax, andanti-oxidants, such as substituted diphenyl amine (reported by DuPont tobe available commercially from Uniroyal Chemical under the tradenameNAUGARD 445). Commercial examples of such rubber tougheners includeVAMAC VMX 1012 and VCD 6200 rubbers, and these may be used too.

The exemplary compositions containing methylene beta-ketoester monomermay also optionally include other additives, such as plasticizingagents, thixotropic agents, natural or synthetic rubbers, filler agents,and reinforcing agents, etc. Such additives are well known to thoseskilled in the art.

The exemplary compositions containing methylene beta-ketoester monomermay optionally include at least one plasticizing agent that impartsflexibility to the polymer formed from the methylene beta-ketoestermonomer. The plasticizing agent preferably contains little or nomoisture and should not significantly affect the stability orpolymerization of the monomer. Such plasticizers are useful inpolymerized compositions to be used in any application in whichflexibility of the adhesive or polymer product is desirable.

Examples of suitable plasticizers include, without limitation, acetyltributyl citrate, dimethyl sebacate, triethyl phosphate, tri(2-ethylhexyl)phosphate, tri (p-cresyl) phosphate, glyceryl triacetate,glyceryl tributyrate, diethyl sebacate, dioctyl adipate, isopropylmyristate, butyl stearate, lauric acid, trioctyl trimellitate, dioctylglutarate, and mixtures thereof. Preferred plasticizers are tributylcitrate and acetyl tributyl citrate. In embodiments, suitableplasticizers include polymeric plasticizers, such as polyethylene glycol(PEG) esters and capped PEG esters or ethers, polyester glutarates andpolyester adipates.

The addition of plasticizing agents in amounts less than about 60 weight%, or less than about 50 weight %, or less than about 30 weight %, orless than about 10 weight %, or less than about 5 weight %, or less thanabout 1 weight % or less, provides increased film strength (e.g.,toughness) of the polymerized monomer over polymerized monomers nothaving plasticizing agents.

The exemplary compositions containing methylene beta-ketoester monomermay also optionally include at least one thixotropic agent, i.e., theproperty of exhibiting a high fluidity during deformation by force of asprayer, roller or trowel, but losing the fluidity when left at rest.Suitable thixotropic agents are known to the skilled artisan andinclude, but are not limited to, silica gels such as those treated witha silyl isocyanate. Examples of suitable thixotropic agents aredisclosed in, for example, U.S. Pat. Nos.: 4,720,513 or 4,510,273, thedisclosures of which are hereby incorporated in their entireties.

The exemplary compositions containing methylene beta-ketoester monomermay also optionally include at least one natural or synthetic rubber toimpart impact resistance, which is preferable especially for industrialcompositions of the present invention. Suitable rubbers are known to theskilled artisan. Such rubbers include, but are not limited to, dienes,styrenes, acrylonitriles, and mixtures thereof. Examples of suitablerubbers are disclosed in, for example, U.S. Pat. Nos. 4,313,865 and4,560,723, the disclosures of which are hereby incorporated in theirentireties.

The exemplary compositions containing methylene beta-ketoester monomermay also optionally comprise one or more other reinforcing agents (e.g.,fibrous reinforcements) other than natural or synthetic rubber to impartimpact resistance and/or to impart structural strength or to provideshape or form. Examples of such agents are well known in the art.Examples of suitable fibrous reinforcement include PGA microfibrils,collagen microfibrils, cellulosic microfibrils, and olefinicmicrofibrils. The compositions may also contain colorants such as dyes,pigments, and pigment dyes. Examples of suitable colorants include6-hydroxy-5-[(4-sulfophenyl)axo]-2-naphthalene-sulfonic acid (FD+CYellow No. 6);9-(o-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3H-xanthen-3-onemonohydrate (FD+C Red No. 3); and2-(1,3-dihydro-3-oxo-5-sulfo-2H-indol-2-ylidene)-2,3-dihydro-3-oxo-1H-indo1e-5-sulfonic acid (FD+C Blue No. 2), wherein the suitable colorantshould not destabilize the monomer.

The exemplary compositions containing methylene beta-ketoester monomermay also optionally include at least one thickening agent. Suitablethickeners include, for example, polycyanoacrylates, polylactic acid,poly-1,4-dioxa-2-one, polyoxalates, polyglycolic acid, lactic-glycolicacid copolymers, polycaprolactone, lactic acid-caprolactone copolymers,poly-3-hydroxybutyric acid, polyorthoesters, polyalkyl acrylates,copolymers of alkylacrylate and vinyl acetate, polyalkyl methacrylates,and copolymers of alkyl methacrylates and butadiene. Examples of alkylmethacrylates and acrylates are poly(2-ethylhexyl methacrylate) andpoly(2-ethylhexyl acrylate), also poly(butylmethacrylate) andpoly(butylacrylate), also copolymers of various acrylate andmethacrylate monomers, such aspoly(butylmethacrylate-co-methylacrylate).

To improve the cohesive strength of adhesives formed from thecompositions containing methylene beta-ketoester monomer, difunctionalmonomeric cross-linking agents may be added to the monomer compositionsof this invention. Such crosslinking agents are known. U.S. Pat. No.3,940,362 to Overhults, which is hereby incorporated in its entirety byreference, discloses such crosslinking agents.

Other compositions and additives contemplated herein, include additionalstabilizers, accelerators, plasticizers, fillers, opacifiers,inhibitors, thixotrophy conferring agents, dyes, fluorescence markers,thermal degradation reducers, adhesion promoters, thermal resistanceconferring agents and combinations thereof, and the like, some of whichare exemplified by U.S. Pat. Nos. 5,624,669; 5,582,834; 5,575,997;5,514,371; 5,514,372; 5,312,864 and 5,259,835, the disclosures of all ofwhich are hereby incorporated in their entirety by reference.

Depending on whether the composition is a monomer-based composition(e.g., inks, adhesives, coatings, sealants or reactive molding) or apolymer-based composition (e.g., fibers, films, sheets, medicalpolymers, composite polymers and surfactants), one having ordinary skillin the art will have the knowledge and skill by which to formulate suchcompositions and/or products without undue experimentation havingsuitable amounts, levels and combinations of the above types ofadditives and components.

Additionally, polymerizable compositions may be formulated to includeadditives such as acidic stabilizers, a free radical stabilizers, asequestering agents, a cure accelerators, rheology modifiers, aplasticizing agents, a thixotropic agents, natural rubbers, syntheticrubbers, filler agents, reinforcing agents and the like. Such additivesare provided at levels sufficient to achieve the desired results whichcan readily be determined by those having skill in the art.

For certain exemplary embodiments, an acidic stabilizer is present in aconcentration of about 0.1 ppm to about 100 ppm, about 0.1 ppm to about25 ppm, or about 0.1 ppm to about 15 ppm, by weight of the composition.

For certain exemplary embodiments, a free radical stabilizer is presentin a concentration selected from about 0.1 ppm to about 10000 ppm, about0.1 ppm to about 3000 ppm, about 0.1 ppm to 1500 ppm, about 0.1 ppm toabout 1000 ppm, about 0.1 ppm to about 300 ppm, or about 0.1 ppm toabout 150 ppm, by weight of the composition.

For certain exemplary embodiments, a sequestering agent, such as a crownether, a silyl crown, a calixarene, a polyethylene glycol, or acombination thereof may be utilized.

For certain exemplary embodiments, a cure accelerator, such as sodiumacetate, potassium acetate, tetrabutyl ammonium fluoride, tetrabutylammonium chloride, tetrabutyl ammonium hydroxide, a benzoate salt, a2,4-pentanedionate salt, a sorbate salt, and a propionate salt, may beutilized.

For certain exemplary embodiments, a rheology modifier, such ashydroxyethyl cellulose, ethyl hydroxyethyl cellulose, methyl cellulose,a polymeric thickener, and pyrogenic silica, may be utilized.

Exemplary polymerizable compositions are stable at 25° C. and atatmospheric pressure for more than 10 days, more than 15 days, more than20 days, more than 25 days, or more than 30 days. Certain exemplaryembodiments may exhibit a shelf life of up to one year, or up to twoyears. Certain exemplary embodiments may be tested for stability atelevated temperature, e.g., 82° C., at atmospheric pressure. Certainexemplary embodiments may exhibit elevated temperature stability formore than 2 hours.

Certain exemplary embodiments disclosed herein relate to polymers andpolymer products formed by polymerization of the polymerizablecompositions comprising the methylene beta-ketoester monomers.

Polymers and polymer products envisioned include coatings, paints,fibers, composites, textile fibers, water-treatment polymers, inkcarriers, paint carriers, packaging films, moldings, medical polymers,polymer films, polymer fibers, polymer sheets, and the like. Asdiscussed earlier, the methylene beta-ketoester monomers are capable ofsupporting a vast array of products due to the activity of the methylenegroup and the ability to vary the functional groups R, R′ as shown inthe structure of the repeating unit:

wherein R and R′ are independently C₁-C₁₅ alkyl, C₂-C₁₅ alkenyl,halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15 alkyl), eachof which may be optionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl,C₁-C₁₅ alkoxy, C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano, acyloxy,carboxy, or ester.

Oligomeric Complex Products

The reaction of the precursor beta-ketoester with the source offormaldehyde may result in an oligomeric complex which is subsequentlycracked to obtain the desired methylene beta-ketoester monomer. Certainoligomeric complexes are capable of being efficiently vaporized or“cracked” into high purity monomers of2-methylene-1,3-disubstituted-propane-1,3-dione by rapid vaporization asdescribed herein.

As such, the invention provides an oligomeric complex prepared byreacting a 1,3-disubstituted-propane-1,3-dione with a source offormaldehyde; optionally in the presence of heat transfer agent;optionally in the presence of an acidic or basic catalyst; andoptionally in the presence of an acidic or non-acidic solvent. Incertain embodiments, the oligomeric complex comprises between 2 and 12repeat units that are able to yield monomer upon cracking

The invention further provides an oligomeric complex prepared byreacting a 1,3-disubstituted-propane-1,3-dione with a source offormaldehyde in a substantial absence of acidic solvent; optionally inthe presence of heat transfer agent; optionally in the presence of anacidic or basic catalyst; and optionally in the presence of a non-acidicsolvent. In certain embodiments, the substantial absence of acidicsolvent represents less than 1.0%, less than 0.5%, less than 0.2% orless than 0.1% by weight acidic solvent as compared to the totalcomposition of the reaction mixture.

EXAMPLES

The structures, materials, compositions, and methods described hereinare intended to be representative examples of the invention, and it willbe understood that the scope of the invention is not limited by thescope of the examples. Those skilled in the art will recognize that theinvention may be practiced with variations on the disclosed structures,materials, compositions and methods, and such variations are regarded aswithin the ambit of the invention.

Analytical Methods

The structures of monomers of this invention were confirmed using one ormore of the following procedures.

NMR

Samples were diluted in deuterated chloroform prior to 1H NMRspectroscopy at 300 MHz (Bruker). A more concentrated sample was alsoprepared in a solution of 0.01 M Cr(III) acetoacetonate in deuteratedchloroform and was analyzed by quantitative 13C NMR spectroscopy at 75MHz. Samples were not purified.

Abbreviations and Acronyms

A comprehensive list of the abbreviations used by organic chemists ofordinary skill in the art appears in The ACS Style Guide (third edition)or the Guidelines for Authors for the Journal of Organic Chemistry. Theabbreviations contained in said lists, and all abbreviations utilized byorganic chemists of ordinary skill in the art are hereby incorporated byreference. For purposes of this invention, the chemical elements areidentified in accordance with the Periodic Table of the Elements, CASversion, Handbook of Chemistry and Physics, 67th Ed., 1986-87.

More specifically, when the following abbreviations are used throughoutthis disclosure, they have the following meanings:

atm atmosphere

br s broad singlet

C Celsius

d doublet

dd doublet of doublets

MM substituted 3-methylene-2,4-pentanebeta-ketoester

HQ hydroquinone

GC-MS Gas Chromatography-Mass Spectroscopy

g gram

h hour, hours

¹H NMR proton nuclear magnetic resonance

J coupling constant (NMR spectroscopy)

L liter

M mol·L⁻¹ (molar)

m multiplet

MHz megahertz

min minute, minutes

mL milliliter

mM millimolar

mol mole

MS mass spectrum, mass spectroscopy

m/z mass-to-charge ratio

N equivalents·L⁻¹ (normal)

NMR Nuclear Magentic Resonance

pH negative logarithm of hydrogen ion concentration

q quartet

rt room temperature

s singlet

t triplet

RB, RBF round bottom flask

The following concrete examples were made in accordance with thereaction scheme set forth above.

Example 1. Reaction of Ethyl 4,4-Dimethyl-3-Oxopentanoate andFormaldehyde

A 250 mL round bottom flask was equipped with a heating mantle, anoverhead stirrer equipped with a teflon paddle, a thermocouple and anoutlet adapter with attached rubber tubing vented to the back of thehood. The round bottom flask was placed on a heating mantle. A 50 gsample of ethyl pivaloylacetate (i.e., 4,4-dimethyl-3-oxopentanoate),4.8 g of paraformaldehyde and 0.06 g of zinc acetate were added to theround bottom flask to form a heterogeneous mixture. After 2 minutes ofmixing the temperature was set to 100° C. and heating was started. After5 minutes of reaction time at a temperature of 55° C., the mixture beganto clarify. After an additional 30 seconds an exotherm was observed atan approximate temperature of 65.5° C. At this point heating was stoppedand the reaction was allowed to proceed. A maximum temperature of 122.1°C. was attained after 8 minutes. The crude product was allowed to coolto room temperature at which time a viscous light yellow liquid wasobtained. An aliquot of this material was analyzed by 1H and 13C NMR.This oligomeric material was then depolymerized/cracked as detailedbelow.

A 4-neck 250 mL round bottom flask was fitted with a mechanical stirrer,an addition funnel, a thermocouple attached to a temperature controller,a Claisen distillation head, vacuum adapater connected to a one-neck 100mL round bottom flask placed in an ice bath. The system was evacuated to100 mmHg after which heat was then applied via a heating mantle. Whenthe set temperature reached 190° C., the oligomer was slowly added tothe hot cracking flask. The resulting crude monomer was simultaneouslycracked and distilled to the receiving flask. During the distillationphase an average head temperature of 155° C. was observed. After theaddition was completed, the heat source was turned off and the systemwas allowed to cool to room temperature. The crude pale green monomerwas then analyzed by ¹H and ¹³C NMR.

The following monomer was obtained.

FIGS. 1 and 2 show the ¹H, ¹³C, and DEPT-135 NMR spectra of theisolation step (“crack”) in this reaction. Peaks at 5.6 and 6.3 ppm inthe ¹H and 126 ppm in the ¹³C NMR spectrum correspond to the geminal CH₂species and the quaternary peak at 142 ppm are consistent with theproduct.

Example 2. Reaction of Ethyl 3-Oxo-3-Phenylpropanoate with Formaldehyde

The reaction scheme disclosed herein was performed using ethyl3-oxo-3-phenylpropanoate and formaldehyde (obtained fromparaformaldehyde). The following monomer was obtained.

FIGS. 3 and 4 show peaks at 6.1 and 6.7 ppm in the ¹H NMR spectrum and apeak at 131 ppm in the ¹³C NMR spectrum corresponding to the geminal CH₂peak and a quaternary peak at 142 ppm, which are consistent with theproduct.

Example 3. Reaction of ethyl 3-oxohexanoate with formaldehyde

The reaction scheme disclosed herein was performed using ethyl3-oxohexanoate and formaldehyde (obtained from paraformaldehyde). Thefollowing monomer was obtained.

FIG. 5 shows the ¹H NMR spectrum. Peaks at 6.25 and 6.35 ppm areconsistent with the geminal CH₂ of the product.

Example 4. Reaction of Ethyl 3-Oxobutanoate with Formaldehyde

The reaction scheme disclosed herein was performed using ethyl3-oxobutanoate and formaldehyde (obtained from paraformaldehyde). Thefollowing monomer was obtained.

FIG. 6 shows the ¹H NMR spectrum. The two small peaks at 6.4 and 6.5 ppmare consistent with the geminal CH₂ of the product.

Example 5. Reaction of Methyl 3-Oxobuanoate with Formaldehyde

The reaction scheme disclosed herein was performed using methyl3-oxobuanoate and formaldehyde (obtained from paraformaldehyde). Thefollowing monomer was obtained.

FIG. 7 shows the ¹H NMR spectrum. The peaks at 6.4 and 6.5 ppm areconsistent with the geminal CH₂ of the product

Example 6. Reaction of Ethyl 4-Methyl-3-Oxopentanoate with Formaldehyde

The reaction scheme disclosed herein was performed using ethyl4-methyl-3-oxopentanoate and formaldehyde (obtained fromparaformaldehyde). The following monomer was obtained.

FIG. 8 shows the ¹H NMR spectrum. The peaks at 6.15 and 6.35 ppm areconsistent with the geminal CH₂ of the product.

Example 7. Reaction of Ethyl 3-Oxopenanoate with Formaldehyde

The reaction scheme disclosed herein was performed using ethyl3-oxopenanoate and formaldehyde (obtained from paraformaldehyde). Thefollowing monomer was obtained.

FIG. 9 shows the ¹H NMR spectrum. The peaks at 6.3 and 6.4 ppm areconsistent with the geminal CH_(z) of the product.

Example 8. Additional Examples

The reaction scheme disclosed herein is performed using an appropriatebeta-ketoester reactant and a source of formaldehyde to obtain thefollowing monomers.

EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments of the invention described herein. Such equivalents areintended to be encompassed by this invention.

1. A polymerizable composition comprising: at least one methylenebeta-ketoester monomer having the structural formula:

wherein R₁ and R₂ are independently C₁-C₁₅ alkyl, C₂-C₁₅ alkenyl,halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15 alkyl), eachof which may be optionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl,C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, orester; or wherein R₁ and R₂ are taken together with the atoms to whichthey are bound to form a 5-7 membered heterocyclic ring which may beoptionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester;wherein the amount of ketals in the polymerizable composition is lessthan about 100 ppm and/or the amount of latent acid-forming impuritiesin the polymerizable composition is less than about 100 ppm.
 2. Thepolymerizable composition of claim 1, wherein the amount of ketals inthe polymerizable composition is less than about 10 ppm and the amountof latent acid-forming impurities in the polymerizable composition isless than about 10 ppm.
 3. The polymerizable composition of claim 1including a stabilizing amount of at least one stabilizer selected fromthe group consisting of an acidic stabilizer, a vapor phase stabilizer,and a free radical stabilizer.
 4. The polymerizable composition of claim3, wherein the polymerizable composition is an adhesive, a coating, or asealant.
 5. The polymerizable composition of claim 3, wherein the atleast one stabilizer includes the acidic stabilizer selected fromtrifluoromethane sulfonic acid, maleic acid, methane sulfonic acid,difluoro acetic acid, trichloroacetic acid, phosphoric acid,dichloroacetic acid, and chlorodifluoro acid.
 6. The polymerizablecomposition of claim 3, wherein the at least one stabilizer includes thevapor phase stabilizer selected from hydroquinone, methyl hydroquinone,butylated hydroxytoluene, butylated hydroxyanisole.
 7. (canceled) 8.(canceled)
 9. A polymerizable composition comprising: at least onemethylene beta-ketoester monomer having the structural formula:

wherein R₁ and R₂ are independently C₁-C₁₅ alkyl, C₂-C₁₅ alkenyl,halo-(C₁-C₁₅ alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl),heterocyclyl, heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl-(C1-C15 alkyl),heteroaryl or heteroaryl-(C₁-C₁₅ alkyl), or alkoxy —(C1-15 alkyl), eachof which may be optionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅alkyl), C₃-C₆ cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl,heterocyclyl-(C₁-C₁₅ alkyl), aryl, aryl (C₁-C₁₅ alkyl), heteroaryl,C₁-C₁₅ alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, orester; or wherein R₁ and R₂ are taken together with the atoms to whichthey are bound to form a 5-7 membered heterocyclic ring which may beoptionally substituted by C₁-C₁₅ alkyl, halo-(C₁-C₁₅ alkyl), C₃-C₆cycloalkyl, halo-(C₃-C₆ cycloalkyl), heterocyclyl, heterocyclyl-(C₁-C₁₅alkyl), aryl, aryl —(C₁-C₁₅ alkyl), heteroaryl, C₁-C₁₅ alkoxy, C₁-C₁₅alkylthio, hydroxyl, nitro, azido, cyano, acyloxy, carboxy, or ester;wherein the methylene beta-ketoester monomer is a high purity monomerhaving a purity of about 95 weight percent or more.
 10. Thepolymerizable composition of claim 9, wherein the amount of anyanalogous compound having the methylene group of the methylenebeta-ketoester replaced by a hydroxyaklyl group is about 3 mole percentor less, based on the total moles of the monomer.
 11. The polymerizablecomposition of claim 9, wherein any impurities in the monomer, ifpresent, includes an analogous 1,1-disubstituted alkane compound in anamount of about 40 mole percent or more of the impurity.
 12. Thepolymerizable composition of claim 9, wherein the concentration of anyimpurities having a dioxane group is about 2 mole percent or less, basedon the total weight of the methylene beta-ketoester.
 13. Thepolymerizable composition of claim 9, wherein the polymerizablecomposition includes a stabilizing amount of at least one stabilizerselected from the group consisting of an acidic stabilizer, a vaporphase stabilizer, and a free radical stabilizer.
 14. The polymerizablecomposition of claim 9, wherein the polymerizable composition is anadhesive, a coating, or a sealant.
 15. (canceled)
 16. (canceled)
 17. Thepolymerizable composition of claim 9, wherein the amount of ketals inthe polymerizable composition is less than about 100 ppm and/or theamount of latent acid-forming impurities in the polymerizablecomposition is less than about 100 ppm
 18. A method of preparing thepolymerizable composition of claim 1 comprising: forming a methylenebeta-ketoester monomer by reacting i) formaldehyde; and ii) abeta-ketoester; wherein the reaction product has a purity of about 97percent or more wherein the amount of ketals in the reaction product isless than about 100 ppm and/or the amount of latent acid-formingimpurities in the reaction product is less than about 100 ppm.
 19. Themethod of claim 18, wherein the beta-ketoester is ethyl4,4-dimethyl-3-oxopenanoate, ethyl 3-oxo-3-phenylpropanoate, ethyl3-oxohexanoate, ethyl 3-oxobutanoate, methyl 3-oxobutanoate, ethyl4-methyl-3-oxopentanoate, or ethyl 3-oxopentanoate.
 20. A method ofpreparing the polymerizable composition of claim 9 comprising: forming amethylene beta-ketoester monomer by reacting i) formaldehyde; and ii) abeta-ketoester. wherein the reaction product has a purity of about 97percent or more. ing: forming a methylene beta-ketoester monomer byreacting i) formaldehyde; and ii) a beta-ketoester. wherein the reactionproduct has a purity of about 97 percent or more.